The new STC will allow Caravan operators worldwide to install the upgrade, which includes a factory-new Pratt & Whitney PT6A-42A engine rated at 850 continuous shaft horsepower; a new, wide-chord, 100-inch diameter Hartzell four-blade propeller; new composite cowling and high-efficiency inlet duct; new 40-percent larger oil cooler; the existing engine mount with a modified horse collar; new engine hose kit; new Blackhawk Hawkeye DigiLog engine gauges; and new Frakes exhaust stacks. The company spent $3 million and 35,000 man-hours developing the conversion.

Blackhawk CEO Jim Allmon said two Caravan customers already have completed contracts for the new upgrade package. Beginning at the NBAA convention, the company will be accepting pre-certification orders and offering a limited number of special pricing packages.

Allmon said the FAA is expected to approve the new STC during this year’s fourth quarter, and approvals from international certification agencies are under way. “These STCs will enable Blackhawk to offer the outstanding capabilities and efficiency of the XP42A package to the entire Cessna Caravan fleet,” he said.

The upgrade significantly expands Caravan performance margins, effectively doubling the aircraft’s rate of climb while using less fuel. Takeoff distances on land or water will be reduced, and takeoff weight, range and true airspeed will increase. Takeoff weight increases by approximately 4 percent, while airspeed is boosted by 15 percent. The converted aircraft also is approved for flight-into-known-icing conditions. “With the stock engine, when you load up with ice, you are going to start drifting down,” Allmon said. “We tested this airplane for an hour with more than five inches of ice on it. The slowest speed that we could maintain at full power was 170 knots.” As part of the test regime Blackhawk test pilots did 115 spins.

The company sees the upgrade of value to operators flying utility and special missions worldwide, ranging from business and passenger flights and freight hauling to air ambulance service, surveillance and patrol and skydiving.

Blackhawk Modifications was founded in 1999 in Waco, Texas. It claims the largest installed fleet of STC’d twin-engine turboprop engine upgrades and to be the largest non-OEM buyer of new Pratt & Whitney Canada turboprop engines in the world. It has an international network of approved dealers and service support centers. –M.H.